At the end of last year on CapX, I documented the constant stream of technological, scientific and medical breakthroughs that are improving the lives of billions of ordinary people. Given all this good news, the real question is why people are so unbelievably pessimistic.

Judging by a 2016 poll of close to 20,000 people in some of the world’s richest countries, you could barely overstate the extent of the gloominess. In response to the question “All things considered, do you think the world is getting better or worse, or neither getting better nor worse?”, just 10 per cent in Sweden, 6 per cent in the US, 4 per cent in Germany and 3 per cent in France thought things were getting better. Why? Because, it turns out, we are pessimists by nature.

Over the last 200 years or so, the world has experienced previously unimaginable improvements in standards of living. The process of rapid economic growth started in Europe and America, but today some of the world’s fastest growing countries can be found in Asia and Africa – lifting billions of people from absolute poverty. Historical evidence, therefore, makes a potent case for optimism. Yet, pessimism is everywhere. As the British author Matt Ridley noted in The Rational Optimist:

The bookshops are groaning under ziggurats of pessimism. The airwaves are crammed with doom. In my own adult lifetime, I have listened to the implacable predictions of growing poverty, coming famines, expanding deserts, imminent plagues, impending water wars, inevitable oil exhaustion, mineral shortages, falling sperm counts, thinning ozone, acidifying rain, nuclear winters, mad-cow epidemics, Y2K computer bugs, killer bees, sex-change fish, global warming, ocean acidification and even asteroid impacts that would presently bring this happy interlude to a terrible end. I cannot recall a time when one or other of these scares was not solemnly espoused by sober, distinguished and serious elites and hysterically echoed by the media. I cannot recall a time when I was not being urged by somebody that the world could only survive if it abandoned the foolish goal of economic growth. The fashionable reason for pessimism changed, but the pessimism was constant. In the 1960s the population explosion and global famine were top of the charts, in the 1970s the exhaustion of resources, in the 1980s acid rain, in the 1990s pandemics, in the 2000s global warming. One by one these scares came and (all but the last) went.

Ridley raises a more specific point that general pessimism: Why are we as a species so willing to believe in doomsday scenarios that virtually never materialise?

The Chairman of the X Prize Foundation, Peter H. Diamandis, offers one plausible explanation. Human beings are constantly bombarded with information. Because our brains have a limited computing power, they have to separate what is important, such as a lion running toward us, from what is mundane, such as a bed of flowers. Because survival is more important than all other considerations, most information enters our brains through the amygdala – a part of the brain that is “responsible for primal emotions like rage, hate and fear.” Information relating to those primal emotions gets our attention first because the amygdala “is always looking for something to fear.” Our species, in other words, has evolved to prioritise bad news.

The Harvard University psychologist Steven Pinker has noted that the nature of cognition and nature of news interact in ways that make us think that the world is worse than it really is. News, after all, is about things that happen. Things that did not happen go unreported. As Pinker points out, we “never see a reporter saying to the camera, ‘Here we are, live from a country where a war has not broken out.’” Newspapers and other media, in other words, tend to focus on the negative. As the old journalistic addage goes, “If it bleeds, it leads.”

To make matters worse, the arrival of social media makes bad news immediate and more intimate. Until relatively recently, most people knew very little about the countless wars, plagues, famines and natural catastrophes happening in distant parts of the world. Contrast that with the 2011 Japanese tsunami disaster, which people throughout the world watched unfold in real time on their smart phones.

The human brain also tends to overestimate danger due to what psychologists call “the availability heuristic” or a process of estimating the probability of an event based on the ease with which relevant instances come to mind. Unfortunately, human memory recalls events for reasons other than their rate of recurrence. When an event turns up because it is traumatic, the human brain will overestimate how likely it is to reoccur.

Consider our fear of terror. According to John Mueller, a political scientist from the Ohio State University, “In the years since 9/11, Islamist terrorists have managed to kill about seven people a year within the United States. All those deaths are tragic of course, but some comparisons are warranted: lightning kills about 46 people a year, accident-causing deer another 150, and drownings in bathtubs around 300.” Yet, Americans continue to fear terror much more than drowning in a bathtub.

Moreover, as Pinker also points out, the psychological effects of bad things tend to outweigh those of the good ones. Ask yourself, how much happier can you imagine yourself feeling? And again, how much more miserable can you imagine yourself to feel? The answer to the latter question is: infinitely. Psychological literature shows that people fear losses more than they look forward to gains; dwell on setbacks more than relishing successes; resent criticism more than being encouraged by praise. Bad, in other words, is stronger than good.

Finally, good and bad things tend to happen on different timelines. Bad things, such as plane crashes, can happen quickly. Good things, such as the strides humanity has made in the fight against HIV/AIDS, tend to happen incrementally and over a long period of time. As Kevin Kelly from Wired has put it, “Ever since the Enlightenment and the invention of Science, we’ve managed to create a tiny bit more than we’ve destroyed each year. But that few percent positive difference is compounded over decades in to what we might call civilisation … [Progress] is a self-cloaking action seen only in retrospect.”

In other words, humanity suffers from a negativity bias or “vigilance for bad things around us.” Consequently, there is a market for purveyors of bad news, be they doomsayers who claim that overpopulation will cause mass starvation, or scaremongers who claim that we are running out of natural resources.

Politicians, too, have realised that banging on about “crises” increases their power and can get them re-elected. It may also lead to prestigious prizes and lucrative speaking engagements. Thus politicians on both Left and Right play on our fears – whether it is a worry that crime is caused by playing violent computer games or that health maladies supposedly caused by the consumption of genetically modified foods.

The negativity bias is deeply ingrained in our brains. It cannot be wished away. The best that we can do is to realise that we are suffering from it.